A liquid crystal display can show an image using electro-optical characteristics of a liquid crystal, which is injected into a space defined by two substrates. The electro-optical characteristics of the liquid crystals appear when electric power is applied thereto. Such a liquid crystal display is classified as one of a variety of types including twisted nematic (TN), super twisted nematic (STN), dynamic scattering mode (DSM), and the aforemented PDLC, for example. Liquid crystal shutters are useful in various applications concerning the transmittance of light through an aperture in which it should be possible to switch the shutter between a low transmission state and a high transmission state, in response to a change in the electric influence.
PDLCs consist of micron-size droplets of low-molecular weight nematic liquid crystals dispersed in a polymer binder system. A PDLC material is sandwiched between substrates having a transparent conducting electrode such as indium tin oxide, to form a shutter. Upon application of a voltage across the electrodes of the shutter, a switching occurs from an opaque, high scattering state to a clear, transparent state. PDLC materials are formed by phase separation of low-molecular weight liquid crystals from a homogeneous solution with pre-polymer or polymer. The size, shape, and density of the liquid crystal droplets depend on the techniques implemented. With existing shutters, solutions have been proposed over the years for selectively providing a tunable lens. Many of the existing devices, however, require the liquid crystal material be aligned on convex curved substrates or concave curved substrates, where it is extremely difficult to align the liquid crystal molecules on the curved substrates. Additionally, most of these devices require linearly polarized light sources in order to operate. Accordingly improvements are needed.